Cylinder firing position locator used in adjusting valve clearances



G. W. VIERS March 9, 1948.

CYLINDER FIRING POSITION LOCATOR USED IN ADJUSTING VALVE CLEARANCE Filed March 22, 1945 2 Sheets-Sheet 1 INVENTOR. 614.5814. 145R;

BY a LL46 Afro Iver:

March 9, 1948.

G. W. VIERS CYLINDER FIRING POSITION LOCATOR USED IN ADJUSTING VALVE CLEARANCE Filed March 22, 1945 2 Sheets-Sheet 2 8 J M H M 4 5 E M 6 a Patented Mar. 9, 1948 CYLINDER FIRING POSITION LOCATOR USED IN ADJUSTING VALVE CLEAR- ANCES Giles W. Viers, Denton, Tex.

Application March 22, 1945, Serial No. 584,222

3 Claims. (Cl. 116-124) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, Without the payment to me of any royalty thereon.

This invention relates to a device utilized in finding which cylinder of a group of cylinders is located with its piston at firing position, to save time in adjusting valve clearances on multi-cylinder engines.

An object of this invention is to provide an improved device arranged to be connected to a magneto, and more particularly to a Scintilla type of magneto mounted on a multi-cylind'er radial engine, for the purpose of quickly ascertaining which cylinder together with its piston are located at or are approaching the firing position, whereby to greatly reduce the timeheretofore required in adjustin valve clearances of the cylinders of such engines.

Another object of this invention is to provide such an indicating device which will simplify the work and aid partly experienced personnel in setting the valves in multi-cylinder engines and thereby shorten the time and lower the cost of valve adjustment.

These and various other objects and advantages are attained with this invention as will become apparent from the following description, taken in connection with the accompanying drawings wherein the invention is shown in its prefered form, it being evident that other arrangements and forms of construction may be resorted to in carryin out the objects and purposes of this invention.

In thedrawings:

Fig. 1 is a perspectiveview showing a Scintilla type magneto along with an exploded perspective view of my indicating device which constitutes the present invention.

Fig. 2 is a perspective view of this device, being partly cut away and in cross-section, to better illustrate the construction.

Fig. 3 is a front elevational View of the device mounted in an operative position on the magneto.

Referring to the drawings, more particularly to Fig. 1, the invention is illustrated in conjunction with a magneto it of the well known Scintilla type whereof the cover has been removed to show the arrangement of the breaker cam and the breaker points and associated elements.

This type or magneto it comprises a housing it having a breaker cam shaft or drive shaft !2, projecting into an end chamber l3 in the end of the magneto housin H. The cam shaft is has a threaded opening it therein, which normally contains the fastening screw (not shown). A breaker cam or cam ring I5 is mounted on the cam shaft l2 and contains a segmental stepdown portion or notch l6 and a projecting portion l'!, the two dividing walls It therebetween being adapted to be aligned with two aligning marks l9 provided on the rim of the magneto housing I l, whereby to locate the firing positions of the cylinders.

The cam surface of cam ring i5 actuates a spring arm 2! which carries a finger 22 at right angles thereto adapted to actuate a resilient breaker arm 23. The breaker arm 23 carries a movable breaker point at which alternately engages and disengages a stationary breaker point 25 provided on a bracket bar 25, during rotation of the cam ring l5.

Current is carried from the magneto coil (not shown) to the stationary breaker oint 25 wherefrom it travels to the movable breaker point 24 and through said arm 23 and through a connector 21 to the distributor. The spring arm and breaker point are carried on an adjustable base 28 which may be adjusted toward and away from the cam 15 by means of set screws 29, whereby adjustment :of the position of the base 28 will vary the spacing of the breaker points 24 and 25.

Lubrication of the cam ring I5 is provided by a wick 3| which may be moved into engagement with said cam ring by means of a hand-actuated plunger 32.

In order to accurately and quickly adjust the valves of the several cylinders of the engine with which the above disclosed type of magnetos are associated, my improved indicating device has been devised. This device, as best seen in Fig. 1, comprises a centering shaft 35 having a screw 36 on one end thereof which is detachably engageable in the threaded opening M provided in the cam shaft. An annular flange or shoulder 3'! is formed on the end of the shaft adjoining the screw 36, and in the operative position abuts the outer end of cam shaft [2. The opposite end of this centering shaft 35 is provided with a slot 38 and a transverse aperture 39 therethrough. The slot 38 receives a T-shaped bar or latch memher ll! which is turnably mounted in the slot by a pin 4| .inserted through said aperture 39.

An aligning collar 43 having a central aperture 44 therein is engageable over the shaft 35, so that said flange 3'! is seated in a recess 45 provided at the inner end of said aperture 44. The collar 43 has a segmental portion 46 pro ecting beyond a segmental recess or notch 41, and these engage and fit, respectively, with the notch l6 and the vided on the collar 43 thereby forming a centering means for the indicator on the collar. The indicator is secured to the collar by means of a plurality of screws 52 which extend through the indicator into threaded openings provided in the outer face of the collar 43.

A spring 53 is mountable over the shaft 35 and is retained thereon by the T-shaped member 40. This spring 53 presses the indicator 48 and the collar 43 toward the magneto and holds the projection 46 of the collar 43 seated in the notch or step [6 of the cam ring 15. Said member 49 is readily turnable in slot 38 to facilitate mounting and dismounting of said spring on said shaft and of the device on the magneto.

The dial or indicator 48 is provided with equally spaced graduation marks of the same number as there are cylinders in the engine, and these marks are preferably provided in the form of radial gauge lines 54, the lines being numbered in accordance with the firing order of the cylinders. In this case of a 14 cylinder radial engine these lines are numbered from 1 to 14 in the order illustrated in the drawings, to match the firing order of the cylinders.

The graduation lines 54 are so arranged that when the indicator 48 is in the proper position relative to the cam shaft It! with its cam Hi, the number on the radial line 54 on the indicator which is aligned with the aligning mark !9 on the housing I I will show the number of the cylinder whereon the valve cam is in position for valve clearances to be adjusted. Furthermore, since the collar 43 and the indicator 48 are held firmly in engagement with the cam l by the spring 53 which is secured in place by the T-shapiad bar 40, when the crank shaft of the engine has been turned through the appropriate angle the successive firing position of each cylinder with its piston at dead center can be readily indicated by aligning that cylinders aligning mark 54 on the indicator 48 with the lower aligning mark IS on the magneto housing, to facilitate the prompt adjustment of valve clearances.

To install this improved indicator it is preferable to proceed as follows:

(1) Remove the customary magneto breaker cover (not shown) from the magneto.

(2) Remove the customary fastening screw and the washer (not shown) from the breaker cam shaft.

(3) Install my novel centering shaft 35 on the breaker cam shaft 12, in place of said removed fastening screw. I

(4) Place my aligning collar 43 and also the indicator 48 over the centering shaft 35, being sure to engage the projection 46 in the recess l6 and the pin 5! in the aperture 59. Fig. 3 in the drawings shows how this device is installed with the aligning line 54 of cylinder No. 1 spaced clockwise from the lower aligning mark E9 on the magneto housing when the breaker cam is in position to fire cylinder No. 1.

(5) Install the spring 53 on shaft 35 and secure it by the retaining bar 40 placed in its holding position as shown in Fig. 3, thereby mounting the indicating device in its operative position on the magneto I9.

(6) After this installation of the indicating device, rotate the crank shaft until one of the radial lines 54 inscribed on the indicator 48 lines up with the lower breaker cam aligning mark I!) on the magneto housing. The number of the line on the indicator is the number of the cylinder on which the valve cam is set in position for valve clearances to be adjusted.

' 'When this device is not in use, insert the centering shaft 35 through the collar 43 and the indicator 43, placing pin 5| in aperture 50, apply the spring 53, and turn bar 40 crosswise of shaft 35, so as to hold all the parts together assembled as a unit, as shown in Fig. 2 of the drawings.

From the above disclosure it will become apparent that various advantages will accrue by the use of this invention, since it will first, greatly reduce the time heretofore required to set valve clearances by the formerly known and used methods; second, it will permit accurate setting of valve clearance for personnel not entirely familiar with the valve action of a radial engine; third, it will enable valves to be set, and also rocker box covers to be replaced, on the one cylinder which is being worked on before proceeding with the other cylinder and will thus eliminate the possibility of replacing such covers on different cylinders and causing defective fits.

I claim:

1. An indicating device arranged for mounting on a magneto including a breaker cam shaft which has a threaded portion at the outer end and carries a cam thereon operably connected with a multi-cylinder radial engine to actuate the cam with the engine, said device comprising a dial-like indicator having markings thereon bearing a definite relation to the numbers of the firing order of the cylinders, a centering shaft having an end removably threaded onto said portion of said cam shaft to mount said indicator thereon, projecting means on said centering shaft coacting with corresponding means on the cam to oblige the indicator to rotate with the cam, marking means on the rim of the magneto housing whereby the marking on the indicator may be set for readily locating the firing position or a cylinder, and means on the centering shaft in cluding a spring and swingable means to retain the spring for holding the indicator in its operative position on the magneto and being arranged to facilitate removal of the device from the cam shaft.

2. An indicating device arranged for mounting on a magneto which includes a housing provided with a cylinder aligning mark and also includes a breaker cam shaft having a threaded bore in its outer end carrying thereon a notched cam which is operably connected with a multi-cylinder radial engine to rotate therewith, said device comprising an indicator having lines to cooperate with said aligning mark for indicating the firing order of cylinders, a centering shaft having its end removably threaded in said bore in the cam shaft to mount said indicator thereon, an aligning collar removably mounted on said centering shaft and having means to fit the notch in the cam and to oblige the indicator to rotate with the cam, a spring on the centering shaft, and means on the outer end of the centering shaft to retain the spring in place and hold the indicator in its operative position on the magneto, said means being readily swingable to facilitate removal of the spring for speedy mounting and dismounting of said device on the magneto.

3. An indicating device arranged ior mounting on a magneto including a breaker cam shaft having thereon a notched cam which is operably connected with a multi-cylinder radial engine to rotate therewith, said device comprising a discshaped indicator for indicating the firing order of the cylinders of said engine, a centering shaft having its end threaded to the cam shaft to mount said indicator thereon, an aligning collar on said centering shaft and having a projecting portion to fit the cam notch and oblige the indicator to rotate with said cam, a spring on the centering shaft, and an element on the outer end of the centering shaft to retain the spring in place thereon and hold the indicator in its operative position on the magneto, said element being turnable so that the spring and shaft and collar are readily mountable on the magneto and readily removable therefrom.

GEES W. VIERS. 20

REFERENCES crrEn UNITED STATES PATENTS Number 

